July 2011 Clinical Oncology Digital Edition by McMahon Group

PRN

Clinical Oncology News • July 2011

Patient Discussions

Words and Their Unique Meanings in Oncology Although both the specific use and choice of words are relevant issues in all of medicine, from communication between health care professionals to physician interactions with patients and the public, words often have a very special and particularly powerful meaning in oncology. This was eloquently discussed by Susan Sontag in her groundbreaking masterpiece, “Illness as Metaphor.”1 For example, consider the word “advanced” in the context of describing an individual patient’s cancer. What

exactly does this mean? As used in a recently published outstanding overview of the need for oncologists to honestly discuss realistic goals for disease management of “advanced incurable” cancer, the word “advanced” implies

reduced fetal body weight, and pre- and post-implantation embryolethality in rats administered pazopanib at doses ≥3 mg/kg/day. In rabbits, maternal toxicity (reduced food consumption, increased post-implantation loss, and abortion) was observed at doses ≥30 mg/kg/day (approximately 0.007 times the human clinical exposure). In addition, severe maternal body weight loss and 100% litter loss were observed at doses ≥100 mg/kg/day (0.02 times the human clinical exposure), while fetal weight was reduced at doses ≥3 mg/kg/day (AUC not calculated). 8.3 Nursing Mothers: It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk and because of the potential for serious adverse reactions in nursing infants from VOTRIENT, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother. 8.4 Pediatric Use: The safety and effectiveness of VOTRIENT in pediatric patients have not been established. In repeat-dose toxicology studies in rats including 4-week, 13-week, and 26-week administration, toxicities in bone, teeth, and nail beds were observed at doses ≥3 mg/kg/day (approximately 0.07 times the human clinical exposure based on AUC). Doses of 300 mg/kg/day (approximately 0.8 times the human clinical exposure based on AUC) were not tolerated in 13- and 26-week studies with rats. Body weight loss and morbidity were observed at these doses. Hypertrophy of epiphyseal growth plates, nail abnormalities (including broken, overgrown, or absent nails) and tooth abnormalities in growing incisor teeth (including excessively long, brittle, broken and missing teeth, and dentine and enamel degeneration and thinning) were observed in rats at ≥30 mg/kg/day (approximately 0.35 times the human clinical exposure based on AUC) at 26 weeks, with the onset of tooth and nail bed alterations noted clinically after 4 to 6 weeks. 8.5 Geriatric Use: In clinical trials with VOTRIENT for the treatment of RCC, 196 subjects (33%) were aged ≥65 years, and 34 subjects (6%) were aged >75 years. No overall differences in safety or effectiveness of VOTRIENT were observed between these subjects and younger subjects. However, patients >60 years of age may be at greater risk for an ALT >3 X ULN. Other reported clinical experience has not identified differences in responses between elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out. 8.6 Hepatic Impairment: The safety and pharmacokinetics of pazopanib in patients with hepatic impairment have not been fully established. In clinical studies for VOTRIENT, patients with total bilirubin ≤1.5 X ULN and AST and ALT ≤2 X ULN were included [see Warnings and Precautions (5.1)]. An interim analysis of data from 12 patients with normal hepatic function and 9 with moderate hepatic impairment showed that the maximum tolerated dose in patients with moderate hepatic impairment was 200 mg per day [see Clinical Pharmacology (12.3) of full prescribing information]. There are no data on patients with severe hepatic impairment [see Dosage and Administration (2.2)]. 8.7 Renal Impairment: Patients with renal cell cancer and mild/moderate renal impairment (creatinine clearance ≥30 mL/min) were included in clinical studies for VOTRIENT. There are no clinical or pharmacokinetic data in patients with severe renal impairment or in patients undergoing peritoneal dialysis or hemodialysis. However, renal impairment is unlikely to significantly affect the pharmacokinetics of pazopanib since <4% of a radiolabeled oral dose was recovered in the urine. In a population pharmacokinetic analysis using 408 subjects with various cancers, creatinine clearance (30-150 mL/min) did not influence clearance of pazopanib. Therefore, renal impairment is not expected to influence pazopanib exposure, and dose adjustment is not necessary. 10 OVERDOSAGE Pazopanib doses up to 2,000 mg have been evaluated in clinical trials. Dose-limiting toxicity (Grade 3 fatigue) and Grade 3 hypertension were each observed in 1 of 3 patients dosed at 2,000 mg daily and 1,000 mg daily, respectively. Treatment of overdose with VOTRIENT should consist of general supportive measures. There is no specific antidote for overdosage of VOTRIENT. Hemodialysis is not expected to enhance the elimination of VOTRIENT because pazopanib is not significantly renally excreted and is highly bound to plasma proteins. 13 NONCLINICAL TOXICOLOGY 13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility: Carcinogenicity studies with pazopanib have not been conducted. However, in a 13-week study in mice, proliferative lesions in the liver including eosinophilic foci in 2 females and a single case of adenoma in another female was observed at doses of 1,000 mg/kg/day (approximately 2.5 times the human clinical exposure based on AUC). Pazopanib did not induce mutations in the microbial mutagenesis (Ames) assay and was not clastogenic in both the in vitro cytogenetic assay using primary human lymphocytes and in the in vivo rat micronucleus assay. Pazopanib may impair fertility in humans. In female rats, reduced fertility including increased pre-implantation loss and early resorptions were noted at dosages ≥30 mg/kg/day (approximately 0.4 times the human clinical exposure based on AUC). Total litter resorption was seen at 300 mg/kg/ day (approximately 0.8 times the human clinical exposure based on AUC). Post-implantation loss, embryolethality, and decreased fetal body weight were noted in females administered doses ≥10 mg/kg/day (approximately 0.3 times the human clinical exposure based on AUC). Decreased corpora lutea and increased cysts were noted in mice given ≥100 mg/kg/day for 13 weeks and ovarian atrophy was noted in rats given ≥300 mg/kg/day for

(although it does not definitively state) the existence of limited available therapeutic options and an anticipated relatively short survival.2 Although a cancer specialist or someone with a clear understanding of

26 weeks (approximately 1.3 and 0.85 times the human clinical exposure based on AUC, respectively). Decreased corpora lutea was also noted in monkeys given 500 mg/kg/day for up to 34 weeks (approximately 0.4 times the human clinical exposure based on AUC). Pazopanib did not affect mating or fertility in male rats. However, there were reductions in sperm production rates and testicular sperm concentrations at doses ≥3 mg/kg/ day, epididymal sperm concentrations at doses ≥30 mg/kg/day, and sperm motility at ≥100 mg/kg/day following 15 weeks of dosing. Following 15 and 26 weeks of dosing, there were decreased testicular and epididymal weights at doses of ≥30 mg/kg/day (approximately 0.35 times the human clinical exposure based on AUC); atrophy and degeneration of the testes with aspermia, hypospermia and cribiform change in the epididymis was also observed at this dose in the 6-month toxicity studies in male rats. 17 PATIENT COUNSELING INFORMATION See Medication Guide. The Medication Guide is contained in a separate leaflet that accompanies the product. However, inform patients of the following: • Therapy with VOTRIENT may result in hepatobiliary laboratory abnormalities. Monitor serum liver tests (ALT, AST, and bilirubin) prior to initiation of VOTRIENT and at least once every 4 weeks for the first 4 months of treatment or as clinically indicated. Inform patients that they should report any of the following signs and symptoms of liver problems to their healthcare provider right away. • yellowing of the skin or the whites of the eyes (jaundice), • unusual darkening of the urine, • unusual tiredness, • right upper stomach area pain. • Gastrointestinal adverse reactions such as diarrhea, nausea, and vomiting have been reported with VOTRIENT. Patients should be advised how to manage diarrhea and to notify their healthcare provider if moderate to severe diarrhea occurs. • Women of childbearing potential should be advised of the potential hazard to the fetus and to avoid becoming pregnant. • Patients should be advised to inform their healthcare providers of all concomitant medications, vitamins, or dietary and herbal supplements. • Patients should be advised that depigmentation of the hair or skin may occur during treatment with VOTRIENT. • Patients should be advised to take VOTRIENT without food (at least 1 hour before or 2 hours after a meal). VOTRIENT is a trademark of GlaxoSmithKline.

EDITORIAL BOARD COMMENTARY Maurie Markman, MD Vice President of Patient Oncology Services and National Director for Medical Oncology, Cancer Treatment Centers of America, Philadelphia

this multidimensional and potentially highly emotional topic will (or at least should) appreciate the intent of this term and need for discussion, it is reasonable that individuals without knowledge of the complexity of oncologic management may expand the definition beyond this intentionally specific and narrow meaning. In fact, the term “advanced” has long been used as a component of a standard description of the anatomic stage of cancer at diagnosis. So, a patient with a “stage III ovarian cancer” is said to have an “advanced-stage cancer.” Yet, in this specific clinical setting, more than 70% of patients are expected to achieve major objective responses (eg, decrease in the size of measurable tumor masses, disappearance of ascites) and subjective responses (eg, decrease in pain and improved appetite and overall quality of life) to primary therapy (surgery plus chemotherapy), with an anticipated median overall survival currently exceeding 3 to 5 years. This is based on the reported extent of residual disease following initial surgical cytoreduction.3 Surely, in this context the use of the words “advanced cancer” to explain the extent of disease at the time of an ovarian cancer diagnosis is meant to convey a different meaning from the identical term employed to suggest the appropriate need for end-of-life discussions. Furthermore, similar concerns can be raised about the second powerful word noted above, “incurable.” Again, this term (like that previously noted for “advanced”) may be used appropriately to denote a situation where options and anticipated survival unfortunately are quite limited. But on objective reflection of the current status associated with the management of a number of malignant diseases, it is relevant to acknowledge that even some unquestionably “incurable cancers” are becoming chronic disease processes. In this increasingly common scenario, death will likely ultimately result from progression of the neoplasm (if it does not occur earlier from an unrelated cause). However, extended survival of more than 2 to 3 years may be a very realistic possibility with careful and judicious application of a wide range of therapeutic options—chemotherapy, radiotherapy,